From the fact that display quality is excellent, active matrix type liquid-crystal display elements have been pot on the market for portable terminals, liquid-crystal televisions, projectors, computers and the like. In the active matrix type, TFT (thin film transistor), (metal-insulator-metal), or the like is used for each pixel, and it is important that the liquid-crystal compound or the liquid-crystal composition used in this type has a high voltage holding ratio. In addition, a liquid-crystal display element obtained by combining a VA (Vertical Alignment) mode, an IPS (In Plane Switching) mode, and an OCB (Optically Compensated Bend, Optically Compensated Birefringence) mode to obtain wider viewing angle characteristics and an ECB (Electrically Controlled Birefringence) mode reflective liquid-crystal display element to obtain a brighter display have been proposed. To cope with such a liquid-crystal display element, currently, proposals on a new liquid-crystal compound or liquid-crystal composition are made.
At present, as the liquid-crystal display for smartphones, a fringe field switching made liquid-crystal display device (FFS mode liquid-crystal display device) with high quality which is one type of an IPS mode liquid-crystal display element excellent in visual characteristics is widely used (refer to PTLs 1 and 2). The FFS mode is a mode introduced for improving the low opening ratio and transmittance of the IPS mode, and as the liquid-crystal composition used, a material using a p-type liquid-crystal composition having positive dielectric anisotropy is widely used from the viewpoint of easily lowering a voltage. In addition, since most applications of the FFS mode are for portable terminals, more power saving is strongly demanded, and liquid-crystal element manufacturers are continuously performing active development such as adoption of array using IGZO.
In addition, as the alignment method of the liquid-crystal molecules, a method called a rubbing method is widely used. In this method, by rubbing the surface of the alignment film in a certain direction by rotating a roller wrapped with cloth such as nylon or the like with respect to a thin film obtained by applying art alignment film material such as polyimide and firing the applied material while pushing with a constant pressure, an alignment restricting force is imparted to the liquid-crystal molecules. The exact alignment mechanism at this method, is still not clear, and since there are problems that streaky display unevenness occurs by rubbing the surface of the alignment film, a part of the alignment film material falls off, and then, is mixed into the liquid-crystal layer, and TFT is destroyed by static electricity generated in the array substrate, an alignment imparting method in which rubbing is not performed has been studied. In particular, since alignment can be imparted in a non-contact manner with respect to a photo-alignment film obtained by imparting anisotropy to an alignment film by using ultraviolet rays linearly polarized, development of the photo-alignment film has been progressing as a method for solving the problems of the rubbing method, and the use of the photo-alignment film has been sought even in a horizontal electric field type display element (refer to PTL 3).